Wales - Regional Weather Discussion

[TonyH]

It would probably need a prolonged cold spell in the New Year to get it down to the average of 6c or so, its still above 11c atm.

Edited December 18, 2011 by TonyH

[J10]

Each NW blast will have the effect of reducing the Irish Sea anomaly,

http://weather.unisy...anom-111113.gif

http://weather.unisy...anom-111120.gif

http://weather.unisy...anom-111127.gif

http://weather.unisy...anom-111204.gif

http://weather.unisy...anom-111211.gif

The anomaly peaked in November, with the very mild spell, and has reduced with the recent cold NW winds, but it is still above average.

http://weather.unisy...anddiv=hide_bar (Current)

If we had a very potent N/NW, the milder Irish Sea wouldn't really matter, but in marginal situations it can (and has) make a difference.

For Comparison some previous anomalies (as close as possible to the current date)

2010 http://weather.unisy...anom-101219.gif

2009 http://weather.unisy...anom-091220.gif (different format)

2008 http://weather.unisy...anom-081221.gif

2007 http://weather.unisy...anom-071216.gif

2006 http://weather.unisy...anom-061217.gif

Off topic,but by looking a the SST profiles to the west of Brazil, you see if the temps are above zero a El Nino pattern (06/07) & (09/10), or below zero a La Nina pattern. (07/08) & (10/11) & (11/12)

Frosty here overnight, sunny now, a slight nip in the air, but in the sun, very pleasant.

[TonyH]

Weather guide for west Wales and the central Midlands December 19th to Christmas Day 2011

Headline: Often mild; quite unsettled with some rain at times. A Green Christmas

This weeks guide is less of a headache than the last- with a much more straight forward set up!

Clear and frosty tonight, especially in the Midlands, the frost will have gone before dawn though in west Wales.

Monday will be somewhat milder than of late with a succession of troughs crossing the UK bringing spells of rain to all parts.Quite windy. Clearing on Monday evening, but probably too much breeze for much in the way of frost, and a few showers keep going for west Wales.

The brief ridge gives a dry and possibly frosty start to Tuesday, but cloud increases during the afternoon, although rain should hold off until the evening, so, a dry bright day for the Midlands.

From Tuesday night we are in very mild Tropical maritime air, flowing between a large high to our south and a mid Atlantic low pressure system. Some rain or drizzle at times Tuesday night through to early Friday really, although very little for the Midlands, where it may also brighten from time to time, but a mostly cloudy and rather damp spell for west Wales. Very mild, temperatures above 11c both Wednesday and Thursday.

The. by now, weak cold front finally gets through later on Friday, bringing a spell of rain, but probably not much again for the Midlands, and also a cool down, with the chance of a slight frost first thing on Christmas Eve.

The big day looks like seeing a mild west or SW flow over us, so no snow or even frost, most definitely a Green Christmas!

Edited December 18, 2011 by TonyH

[J10]

Can't really disagree with Tony H excellent summary above.

But Christmas Day may well feature the colder weather currently suggested for Christmas Eve. SO while the pattern is fairly straightforward ,timings are not exact atm.

But as I said yesterday a mild Christmas is odds on.

[SnowStorm(Jamie)]

Off topic,but by looking a the SST profiles to the west of Brazil, you see if the temps are above zero a El Nino pattern (06/07) & (09/10), or below zero a La Nina pattern. (07/08) & (10/11) & (11/12)

Frosty here overnight, sunny now, a slight nip in the air, but in the sun, very pleasant.

Thanks for posting those links, the warmer sea surface temperatures over the Irish sea certainly has been a problem this month so far. Looking at the DEC 2010 link it clearly shows the colder sea surface temperatures over the Irish sea which was the result of cold winds from N/NE/E.

Hopefully we will further see the cooling of the sea surface temperatures around Wales, which an easterly could well do later into the winter- but there are no guarantees on this yet. The possibilty of the breakdown of the polar vortex eventually with cold being ejected out of the pole is promising, however i have read that La Ninia's tend to drive a milder end to winter - So perhaps the answer of whats to come for the rest of the winter lies somwhat between the two of those signals. Its certainly going to be interesting to see how this plays out.

A few showers across Wales now as a trough moves through in the flow

[J10]

Thanks for posting those links, the warmer sea surface temperatures over the Irish sea certainly has been a problem this month so far. Looking at the DEC 2010 link it clearly shows the colder sea surface temperatures over the Irish sea which was the result of cold winds from N/NE/E.

Hopefully we will further see the cooling of the sea surface temperatures around Wales, which an easterly could well do later into the winter- but there are no guarantees on this yet. The possibilty of the breakdown of the polar vortex eventually with cold being ejected out of the pole is promising, however i have read that La Ninia's tend to drive a milder end to winter - So perhaps the answer of whats to come for the rest of the winter lies somwhat between the two of those signals. Its certainly going to be interesting to see how this plays out.

A few showers across Wales now as a trough moves through in the flow

Moderate to Strong La Nina can tend to have a mild end to winter, and also can have the effect of not allowing Greenland High and a lack of Northerly blocking (don't ask to explain why), and this have the effect of us have not having potent Northerlies. However countrering this the Jet Stream has consistently been a long way south over recent years, increasing the chance of cold weather over the UK.

Glacier Point in the official NW forecast has always maintained that this winter would be colder later on, http://www.netweathe...mary-2011;sess=

and that December could be the mildest month. Given the underlying synoptic pattern, the whole of December could have been like the week ahead, and it hasn't turned out too bad.

Of course this doesn't guarantee anything, as it has been know for a LRF to go awry.

[SnowStorm(Jamie)]

Moderate to Strong La Nina can tend to have a mild end to winter, and also can have the effect of not allowing Greenland High and a lack of Northerly blocking (don't ask to explain why), and this have the effect of us have not having potent Northerlies. However countrering this the Jet Stream has consistently been a long way south over recent years, increasing the chance of cold weather over the UK.

Glacier Point in the official NW forecast has always maintained that this winter would be colder later on, http://www.netweathe...mary-2011;sess=

and that December could be the mildest month. Given the underlying synoptic pattern, the whole of December could have been like the week ahead, and it hasn't turned out too bad.

Of course this doesn't guarantee anything, as it has been know for a LRF to go awry.

Indeed it certainly has been a theme that GP has maintained with regards to colder later in winter rather than the start. A great & detailed forecast as always also.

2.8C here currently with some scattered showers across Wales this evening/tonight before a frontal system moves across the UK tomorrow from the west bringing heavy rain right across Wales especially in the north:

http://expert-images...121912_1812.gif

[Cwmbran Eira]

So it's looking dry and warmish for Christmas

I would love another cold one with snow but at least it won't be raining. Not great but could be worse

[welshgritter]

It would seem everyone was right and our Winter in the South wont start until Mid Jan! but being long and drawn out in March possibly April.

[benb]

Euughh- looks like something of a green spell coming up...

Couple of pics from Arenig Fawr (854m) from the weekend.

Weather too wild (6hrs odd of heavy snow and hail) on Saturday evening to get up to the bothy, but managed to ski up to the top in a break in the weather on Sunday.

3 hours up, 10 mins down- nice!

[TonyH]

It would seem everyone was right and our Winter in the South wont start until Mid Jan! but being long and drawn out in March possibly April.

Well, they won't be right until after they - cold spell(s) later in the Winter - have actually happened...it may be that we continue see very little in the way of cold even from mid January.

Stunning photos Benb- is that Snowdonia?

[keithlucky]

Yes we oldies TonyH have seen many winters stuck on this gulf stream express train ,question when was the last day of 24hrs dry day cant remember one .

[TonyH]

Less of the Old hey Keith!

27th November was dry here!

[keithlucky]

Less of the Old hey Keith!

27th November was dry here!

2110 ?

[welshgritter]

As long as it hits zero in the night/early hours - im happy.....................it doesnt have to be extreme, just a risk of ice.

just seems like our winter hasnt even kicked in yet.....

[J10]

I'd like to wish Mr Bartlett a warm welcome for Christmas.

But not to warm a welcome as with respect hopefully he will have gone by early January,

[benb]

Stunning photos Benb- is that Snowdonia?

Yep, about 5 miles NW of Bala.

Shame the snow's all going to go as quick as it came...

Mid-winter heatwave for Russia?!

Just getting a bit worried that the prolonged W/SWerlies are going to keep the Irish Sea/ SW Approaches too warm for any prolonged, countrywide cold spell this year.

As others have said on here: the building blocks of the cold spells in the last couple of years have partially been laid by cool/cold SSTs developing early in the season.

Fingers crossed for a significant pattern change soon...

[J10]

Yep, about 5 miles NW of Bala.

Shame the snow's all going to go as quick as it came...

Mid-winter heatwave for Russia?!

Just getting a bit worried that the prolonged W/SWerlies are going to keep the Irish Sea/ SW Approaches too warm for any prolonged, countrywide cold spell this year.

As others have said on here: the building blocks of the cold spells in the last couple of years have partially been laid by cool/cold SSTs developing early in the season.

Fingers crossed for a significant pattern change soon...

The latest look ahead by Glacier Point.

http://forum.netweat...ost__p__2194832

The potential for Northern blocking in January would be very promising for wintry seasonal conditions

[benb]

The latest look ahead by Glacier Point.

http://forum.netweat...ost__p__2194832

The potential for Northern blocking in January would be very promising for wintry seasonal conditions

All a bit technical for me!

But what I think I understand from that is that we might expect the 2nd week of Jan to feature a slow change from the current Atlantic dominated weather to a more blocked situation to the north of the UK, perhaps with HP over Greenland introducing a northerly flow over the UK, or HP over Scandinavia, giving some type of easterly?

[welshgritter]

Come on cold............................

[welshgritter]

People have been saying alot about the jet stream moving? and this will make the Irish sea colder? can anyone shed any light? havent got the foggest?

[Cymro]

Gan ei fod yn hynod dawel ar hyn o bryd hoffwn achub ar y cyfle hwn i ddymuno Nadolig Llawen a Blwyddyn Newydd Dda i chi gyd A pheidiwch ag yfed na bwyta gormod dros yr wÅ·l

Being as its very quiet at the moment, I would like to use this oppertunity to wish you all a very merry Christmas and a Happy New Year and don't be eating or drinking too much over the festive period now

[TonyH]

What a thoroughly wet and windy day, this cold front is really active!

Almost 20mm so far this morning with more to come, could end up one of the wettest days of this year. The wind has changed from SSW a few hours ago to a strong cool northerly, and the temperature has dropped from over 10c this morning to just 5.7c now!

Not a nice afternoon to be driving to the Midlands.

Nadolig Llawen/ Merry Christmas to all on the Welsh forum. Here's hoping that we see some snow and cold in the New Year!

[J10]

Merry Christmas to Everyone, it really belted down here this morning but much direr now

The latest synoptic outlook for the next 7 days is shown on the Alps blog.

http://forum.netweat...-23rd-december/

Predominantly mild with Bartlettesque conditions (at times) sums it up quite well.

[keithlucky]

Happy XMAS TO ALL(including the oldie).